The best representation I've seen is the two dimensional political spectrum, or political compass, which is continuous and does not wrap around in a circle. When the far left and far right appear to have common views, it is almost always in their libertarian views. Trade deals and foreign wars are very authoritarian, so you'll see a lot of common ground there, where Noam Chomsky sounds a lot like Ron Paul. All you have to do to see the differences between these two types is talk about nationalized health care, education, environment, regulation of Wall Street.

So, when it comes to TPP, Obama or Hillary Clinton will sound like most authoritarian Republicans, maybe indistinguishable, but on feminism, human rights, and such, they sound liberal. Warren and Sanders relative to them are libertarian and left.